Five people have been arrested after counterfeit £20 notes were found to be in circulation in Leeds.
Two men and three women were arrested on suspicion of conspiracy to make counterfeit currency during raids at properties in Bramley and Beeston.
Police also seized more than 5,000 in cash and a large amount of electrical equipment suspected to be used to create money.
Detective Inspector Warren Stevenson, of West Yorkshire Police's Crime Division, said: "Although counterfeit notes only form a small percentage of all money in circulation, it causes financial problems, particularly for local businesses.
"It is important that everyone checks the notes they receive and also payments they take to ensure that they are legitimate currency."
Anyone who has information about counterfeit currency is asked to contact West Yorkshire Police on 0845 6060606 or Crimestoppers anonymously on 0800 555111